Process of making artificial stone, &amp;c.



UNITED STATES l atentedfiovember 17, 1903.

PATENT OFFIC EDGAR HOUSE SUTGLIFFE, OF LEIGH, ENGLAND.

aPECJEFIGATION forming part of Letters Patent N 0. 744,432, datedNovember 17, 1903.

Application filed February 17. 1903.

To a whom 252? may concern: I

Be it known that I, EDGAR RoUsE SUT- oLIFFu, a subject of the King ofGreat Britain, residing at Leigh, in the county of Lancaster, England,have invented new and useful Improvements in Processes of MakingArtificial Stone from Material Containing Calcareous Cements, of whichthe following is a specification.

This invention relates to a process for making artificial stone, bricks,paving-flags, and the like in which the binding material is a calcareouscement, preferably that known commonly as Portland cement, and has forits object, first, the prod uction of the finished articles in a muchshorter space. of time; secondly, the production of better goods, and,thirdly, the elimination or reduction of the quantity of waste goodswhich has hitherto resulted from the imperfect processes at pres ent inuse. The materials used for making this class of goods are usuallyrefuse materials-such as destructor clinker, ashes, slag, and thelikethough better class material is used for making a better class brickor slab such, for instance, as sand, gravel, granite chips, and thelike. This material has been mixed with a proportion of the cementmolded into flags or blocks of the required size and shape and thenstacked in suitable places to allow of them becoming set by the naturalaction of the atmosphere. This is a very lengthy proceeding, cement setin this way not acquiring its full strength until nearly twelve monthsold, and attempts have been made to expedite it. by treatment with heator steam in receptacles where the blocks may be surrounded'withsteam ofvarious pressures and temperatures. So far as I am aware, however, notreatment has yet been adopted which is uniformly successful whendealing with calcareous cements, the tendency being for the blocks toburst or crack when subjected to the heat or steam, due probably to theexpansion of lime particles therein which have not been Wholly slaked.

In'the manufacture of goods of this nature by my process the rawmaterial is first thoroughly ground and mixed together, and thecementing "medium, preferably in the form of Portland cement, is thenadded in the proportion, say, of from fifteen to forty per cent.

Serial No. 143,816. (No specimens.)

of the mixture, by measure, the particular heat or steam in the presenceof moisture or simply by mixing the cement with boiling water, themixture being thoroughly stirred all the while to obtain an intimateadmixture of the cement and water. The amount of water should besufficient to form a thick milky liquid or slurry. A small proportion ofquicklime may be used in place of a portion of the cement, in which caseit helps to keep the slurry at a high temperature. After a, short timethe cement is ready for use and may be added to the raw material'of theartificial stone, or the latter may be added to the cement either in adry state or after having itself been treated with water. The two shouldthen be thoroughly mixed until the cement is well distributed throughoutthe mixture. The Whole mixture is stirred until in a slurry statepreparatory to beingmolded into slabs or other goods,which may be doneby hand or preferably on hydraulic or power machines constructed for thepurpose in which considerable pressure is brought to bear on thematerial in the mold, so that the excess moisture is pressed out. Whenmolded,

the blocks of raw material may be taken direct into hardening-chambersfor treatment by heat or steam, this only being possible as a result ofmy preliminary treatment of the cement. Preferably, however, a shortperiod of restsay of about twelve to twenty-four hours-is allowed. Thisenables the goods to receive their initial or first set. In some casesimmersion of the blocks in Water after they have received their initialset maybe found of advantage before the blocks are placed in the finalhardening-chamber, the treatment having to be varied somewhat to suitthe different classes of cement and materials which are made use of.When ready, the molded slabs are placed on suitable wagons and placed ina closed receptacle in which they are subjected to the action of steam,at first gradually and afterward to the full pressure. The pressureemployed is preferably from one hundred pounds to one hundred and fiftypounds per square inch, the time usually from five to ten hours. A lowerpressure of steam will answer the purpose; but in that case a longertime of treatment is necessary. After the treatment in thehardening-chamber the flags or blocks are fully set and quite hard,approaching in strength the qualities of natural sandstone.

The action of the wet heat in the preliminary treatment of the cement isin order to thoroughly slake every particle of lime there may bepresent, as it is the expansion of unsla-ked lime particles which hashitherto caused the goods to blow or crack when undergoing the hardeningtreatment. For this reason it is advantageous that the vessel in whichthe cement is being prepared should be kept heated all the while, thepreparation usually occupying a period of about half an hour. This maybe done either by applying, exterior heat to the vessel, by keeping itfull of steam, or by means ofheating-coils and the like.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. The herein-described process of manufacturing artificial-stone goodshaving a calcareous cement as the binding medium,which consists in firstpreparing the cement in the form of a slurry by boiling it with water,and continuing the heating,mixing it with the raw materials ground to afine state until the cement is fully incorporated therewith, molding themixture into blocks of the required shape, and finally stacking theblocks in position to obtain easy access of air thereto.

2. The herein-described process of manufacturing artificial-stone goodshaving a calcareous cement as a binding medium, which consists inthoroughly grinding and mixing together the raw material, adding theretoa proportion of cement in the form of a slurry previously prepared withhot water and in the presence of heat, further mixing of the materialsuntil the cement is fullyincorporated therewith, molding the mixture tothe required shapes thereby expelling the excess of moisture out of thematerial, and finally treating the molded pieces with heat and steam,all substantially as set forth.

3. The herein-described process for manufacturing artificial-stone goodshaving a calcareous cement as a binding medium, which consists inthoroughly grinding and mixing together the raw material, adding theretoa proportion of cement and quicklime in the form of a slurry previouslyprepared with hot Water and in the presence of heat, further mixing ofthe materials until the cement and quicklime are fully incorporatedtherewith, molding the mixture to the required shapes thereby expellingthe excess of moisture out of the material, and finally treating themolded pieces with heat and steam, all substantially as set forth.

4. The herein-described process of manufactu ring artificial-stone goodshaving a calcareous cement as a binding medium, which consists inthoroughly grinding and mixing together the raw material, adding theretoa proportion of cement in the form of a slurry previously prepared withhot waterand in the presence of heat, further mixing of the materialsuntil the cement is fully incorporated therewith, molding the mixture tothe required shapes thereby expelling the excess of moisture out of thematerial, allowing a short period for the initial setting of the goodsand finally treating the molded pieces with heat and steam, allsubstantially as set forth.

5. The herein-described process of manufacturing artificial-stone goodshaving a calcareous cement as a binding medium, which consists inthoroughly grinding and mixing together the raw material, adding theretoa proportion of cement in the form of a slurry previously prepared withhot water and in the presence of heat, further mixing of the materialsuntil the cement is fully incorporated therewith, molding the mixture tothe required shapes thereby expelling the excess of moisture out of thematerial, allowing a short period for the initial setting of the goods,the submersion of the goods for ashort period in water and finallytreating the molded pieces with heat and steam, all substantially as setforth.

6. The herein-described process of manufacturing artificial-stone goodshaving a calcareous cement as a binding medium, which consists inthoroughly grinding and mixing together the raw material, adding theretofrom fifteen to forty per cent. of Portland cement in the form of aslurry previously prepared with hot water and in the presence of heat,further mixing of the materials until the cement is fully incorporatedtherewith, molding the mixture to the required shapes thereby expellingthe excess of moisture out of the material, and finally treating. themolded pieces with high-pressure steam for a period of from five to tenhours, all substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed myname in presence of two subscribing witnesses.

EDGAR ROUSE SUTCLIFFE.

\Vitnesses:

I. II. ELLISON, II. A. CARR.

